This commit does two things: first, switch a lot of metadata-definition
to use the workspace-package inheritance allowed since Rust 1.64
(including several shared dependencies); second, relax the installation
requirements on `indexmap` and `hashbrown` to allow both to use their
most recent two majors.  Dependents can then install `rustworkx-core`
using either (say) `hashbrown 0.13.2` or `hashbrown 0.14.0` as desired,
and similar between `indexmap 1.9.3` and `indexmap 2.0.0`.

This commit leaves the lock file in the `hashbrown 0.14.0`, `indexmap
2.0.0` state, although note that some other crate dependents still use
`hashbrown 0.12.3` internally, but this doesn't matter for the public
API surface.  I tested it manually in the `hashbrown 0.13.2`, `indexmap
1.9.3` state by updating those two dependencies with:

    cargo update -p '[email protected]' --precise 1.9.3
    cargo update -p '[email protected]' --precise 0.13.2
    cargo update -p '[email protected]'